Do Animals Need a Mesorah?

Birds require a tradition, because the Torah's list of forbidden species can no longer be identified. Mammals are different, and the difference is worth understanding.

The signs are checkable

For animals the Torah gives two physical signs: split hooves and chewing the cud. Both can be examined directly.

So where careful study establishes that a mammal has split hooves and chews its cud exactly as the familiar kosher animals do, it is accepted as a kosher species. No tradition is required to establish that it is kosher.

This is the position of the poskim generally. The Chazon Ish is the notable exception, holding that a tradition is required for mammals too, and some follow him.

This is the reasoning by which animals like bison are accepted.

The second question the signs do not answer

Here is the subtlety. Establishing that an animal is kosher does not establish which kind of kosher animal it is — and that second question has practical consequences.

Kosher mammals divide into b'hemah, domesticated animals, and chaya, wild ones. Two laws turn on the distinction:

• Kissuy hadam — covering the blood after slaughter — applies to a chaya, not to a b'hemah.
• Chelev — certain fats forbidden in a b'hemah but not in a chaya.

Physical signs do not settle which category an animal belongs to. So where there is no clear tradition on that point, the animal is treated as a doubt: the blood is covered without a blessing, and the animal is treated as having chelev.

Both stringencies at once, because a doubt is resolved conservatively in each direction independently.

Why this is a satisfying piece of reasoning

It is worth pausing on the structure. The question "is this animal kosher?" and the question "is it a b'hemah or a chaya?" are answered by different means — one by examination, one by tradition — and the halacha simply applies the right tool to each.

It is also a good illustration of what mesorah is actually for. It is not a general requirement of conservatism. It carries specific information that cannot be recovered by looking.

See also what mesorah is and why a kosher species may still not be certified.